Data processor

Abstract

A data processor includes a cache memory control section which includes: a hit/miss determination section which is supplied with a request for data processing to determine whether data to be processed is present in a cache memory and outputs a cache hit/miss determination result and, if having determined that the data is not present in the cache memory, feeds a read command to make an upper memory control section read the data from the upper memory; a FIFO storage which stores the cache hit/miss determination result and the in-block read position information according to a FIFO system; and a cache memory read/write section which reads the hit/miss determination result and the in-block read position information from the FIFO storage and reads the data from the cache memory, or writes the data from the upper memory control section into the cache memory and outputs the data.

1. A data processor comprising:
 a cache memory; 
 a data processing section; 
 an upper memory control section; and 
 a cache memory control section which is connected to the cache memory, the data processing section, and the upper memory controller, the cache memory control section comprising: 
 a hit/miss determination section which is supplied with a request for data processing from the data processing section and then determines whether data to be processed is present in the cache memory and outputs a cache hit/miss determination result as well as in-block read position information thereof and also, if having determined that the data to be processed is not present in the cache memory, provides the upper memory control section with a read command that permits the upper memory control section to read the data to be processed from the upper memory, the in-block read position information comprising a cache block index and an in-cache block transfer start address; 
 a first in, first out (FIFO) storage section which stores the cache hit/miss determination result and the in-block read position information according to the first in, first out system; and 
 a cache memory read/write section which reads the hit/miss determination result and the in-block read position information from the FIFO storage section and reads the data to be processed from the cache memory, or writes the data to be processed output from the upper memory control section into the cache memory and also outputs the data to be processed, 
 wherein if the cache miss occurs continually, the cache hit/miss determination section generates a subsequent read command prior to a response from the upper memory control section. 
 
     
     
       2. The data processor of  claim 1 ,
 wherein the in-block read position information further comprises the number of the read data pieces for the purpose of burst transfer. 
 
     
     
       3. The data processor of  claim 1 , further comprising a first buffer that stores the read command to be output from the cache hit/miss determination section. 
     
     
       4. The data processor of  claim 1 , further comprising a second buffer which stores the data to be processed which is read from the upper memory and output from the upper memory control section. 
     
     
       5. The data processor of  claim 1 , further comprising a third buffer which is connected to the cache memory read/write section and which stores the data to be processed which is output from the cache memory read/write section. 
     
     
       6. The data processor of  claim 1 , comprising a plurality of the upper memory control sections respectively connected to a plurality of the upper memories, wherein the cache hit/miss determination section generates and outputs the read command for each of the upper memory control sections, and
 the cache memory read/write section receives the data to be processed from each of said plurality of upper memory control sections. 
 
     
     
       7. The data processor of  claim 6 , further comprising a plurality of first buffers which each store the read command output from the cache hit/miss determination section for each of the upper memory control sections. 
     
     
       8. The data processor of  claim 6 , further comprising a plurality of second buffers which are each connected to each of said plurality of upper memory control sections and each store the data to be processed which is read from each of said plurality of upper memories and output.